Catnip (Nepeta cataria) is a hardy, fragrant perennial herb belonging to the mint family. Its vigorous growth habit requires regular management to prevent it from aggressively overtaking garden space. Trimming controls the plant’s spread and encourages a denser, more attractive form. Strategic pruning directs the plant’s energy outward, resulting in a bushier structure with a greater volume of foliage and flowers that contain the active compounds.
Optimal Timing for Pruning
The catnip growing season begins with the first appearance of new growth in early spring, which is the time for the initial major cutback. Cutting back old, dead stems clears the way for vigorous new shoots and helps establish the plant’s overall shape. This early attention encourages a strong base and prevents the plant from becoming leggy.
As the plant matures, a mid-season trim is beneficial after the first flush of flowers begins to fade. Removing these spent flower spikes, known as deadheading, redirects the plant’s energy away from seed production. This encourages the plant to produce a second, more compact, round of growth and flowering.
For gardeners focused on harvesting the most potent material, a specific trim should be timed just as the buds are beginning to swell, right before the flowers fully open. The final seasonal cut occurs in late fall, preparing the plant for winter dormancy. Cut all stems back to two or three inches above the soil line to ensure the plant overwinters successfully and resumes growth the following spring.
Techniques for Routine Maintenance
Maintaining a healthy catnip plant requires using clean, sharp implements like scissors or small hand shears to ensure quick, damage-free cuts. Dull tools can crush the stems, leaving open wounds susceptible to disease or pests. Always sterilize tools with rubbing alcohol before and after use to prevent the transfer of pathogens.
A routine technique for achieving a dense, full plant is “pinching back” the young stems early in the season. Removing the top one or two sets of leaves from a growing tip forces the dormant buds located in the leaf axils to activate. This promotes lateral branching, transforming a single vertical stem into two or more side shoots.
Regular deadheading is the most effective maintenance task for controlling the plant’s spread and appearance. Once the flowers have faded, cutting the entire flower stalk off prevents the plant from setting seed. This action is important because catnip is a prolific self-seeder, and allowing it to drop seeds can lead to an uncontrollable spread.
When making any cut, always locate a leaf node—the point where a leaf meets the stem—and make the cut just above it. Cutting immediately above a node ensures the remaining stem section has a point from which new growth can rapidly emerge. This precise placement facilitates quick healing and optimizes the plant’s energy use.
Harvesting Catnip for Use
Maximizing the desirable compounds in catnip requires careful attention to the timing of the major harvest. The concentration of the essential oil nepetalactone peaks just as the flower buds are forming or when the first few flowers appear. Harvesting at this stage ensures the collected material possesses the highest potency.
The best time of day to perform a large-scale harvest is in the morning, immediately after the dew has evaporated from the leaves. Waiting for the moisture to dry prevents the harvested material from beginning the drying process damp, which reduces the risk of mold or mildew during curing. This timing ensures the essential oils are fully concentrated within the plant tissues, having not been dissipated by the midday sun.
When taking a significant portion of the plant, adhere to the “two-thirds rule” by never removing more than two-thirds of the plant mass in a single harvest. Leaving at least one-third of the foliage intact ensures the plant retains enough surface area for photosynthesis. This conservative approach allows the catnip to quickly recover and regenerate for subsequent harvests.
The physical cutting technique for harvesting differs from routine maintenance because the goal is to secure long stems for easier drying. Select stems six to eight inches long and use a sharp cut above a set of healthy, lower leaves. Ensuring the cut is made above a strong pair of leaves provides the plant with the resources necessary to immediately begin developing new growth points.
Post-Pruning Care and Storage
Following a major trimming or harvest, the remaining catnip plant benefits from a light watering to help it recover from the loss of biomass. Avoid heavy fertilization immediately after cutting, as the plant needs to focus its energy on root and stem recovery rather than rapid new growth. Monitor the newly emerging shoots closely, as soft, tender growth can attract common garden pests.
The harvested stems must be prepared quickly to preserve the nepetalactone content. Gather the cut stems into small, loose bundles and secure them with twine or rubber bands. Hang these bundles upside down in a location that is dark, dry, and has good air circulation to facilitate even drying.
Once the leaves and flowers are completely brittle and crumble easily, they are considered fully cured. Remove the dried material from the stems and store it in an airtight container, such as a glass jar, away from direct light and heat. Proper storage maintains the herb’s potency and fragrance for up to a year.